To play the game, use your mouse to click on the green monster and make it jump. You need to navigate the monster through the level and collect all three mangoes while avoiding obstacles such as spikes and falling off the edge of the platform. When you have collected all three mangoes, you can use the diamond to unlock the door and proceed to the next level. Be sure to watch out for any hazards and try to stay alive as you help the green monster eat all the mangoes!